Reactive Mobile Robots Based on a Visual Servoing Approach

This paper deals with vision based control applied to autonomous mobile robots. The general a proach in robot vision separates vision from control htat ic look and move). A n alternative way consists to specify the problem tn terms of control directly into the sensor frame. This approach seems t o be Q fruitful way for implementing robotics tasks based on reactivity concept. We introduce a low level task specification b y the notion of virtual linkage. This virtual linkage can be expressed b y a set of constraints on the motion of a frame linked to 2he robot with respecf t o a certain frame associated to the environnment. It seems interesting to apply such a vision based control to a mobile robot. The robot considered here is a two wheels driven nonholonomic car? with a camera mounted on 3 d.0.f manipulator. In this siudy we consider the whole mechanical system constituted by the cart and i f s manipulator like a single kinematic chain. So in adding the degrees of freedoom of the a m i o the cart, it becomes possible to fully control the trajectory of the effector. In order to validate this approach, a simulation loo1 has been developped in Mathematica. A first application concerns automatic exploration and cartography of an unknowm room by wall following techniques.